For three months this past winter, cargo vessels pushing up the Stockton Deep Water Channel were forced to drop anchor at nightfall, delaying their arrival at the Port of Stockton.

Why? Radar systems could not distinguish between land and the dense, floating mats of water hyacinth.

Any delay in shipping costs about $2,000 per hour per vessel. If 50 vessels each lost a night's work this past winter, the total cost of the hyacinth infestation might have topped $1 million, a port official said at a state Senate subcommittee hearing in Stockton on Thursday.

"If hyacinth remains an issue, it has the potential to cripple our business," said Jeff Wingfield, the port's director of environmental, government and public affairs.

Nighttime travel into the port resumed in March, but the story illustrates that the hyacinth problem extends beyond small recreational boaters and Delta marinas.

And if you eat, you're affected. The cost of agricultural shipping delays is ultimately passed on to consumers, Wingfield said - to the fertilizer dealers, to the farmers and finally to customers at the grocery store.

Thursday's hearing was convened by state Sen. Cathleen Galgiani, D-Stockton, who chairs the Senate Subcommittee on Invasive Species. Glossy green hyacinth was especially nasty the past two years as the state failed to get the permits necessary to combat the weed with herbicides.

At last, however, five-year permits were obtained earlier this year, and spraying began on Delta waterways in March.

A representative from the state Department of Boating and Waterways expressed optimism that this time, the state will "stay ahead" of the annual infestation.

"But it is a control program," Boating and Waterways acting Director Sylvia Ortega Hunter said. "Eradication is not possible."

Mechanical hyacinth harvesters, like the one that cleared the head of the downtown channel prior to the Asparagus Festival, might be used by the state in the future, but that's still being evaluated, she said.

Rick Hatton, a Danville-based contractor who cleared the channel, said he was paid $6,000 by the city. Not only is the vegetation annoying to boaters, but when it dies and floats into concentrated areas, it often collects garbage and hazardous substances - syringes, paint cans and dead animals, he said during the hearing.

"We need to use the herbicides, but consider moving into the mechanical (methods) too," said Hatton, owner of Aquatic Harvesting.

Wingfield, with the port, said that because consultations with federal wildlife agencies can be lengthy, next time the state should start early.

"Great; we have a five-year permit," he said. "I would say, start working on the next five years. ... Re-engage them (the feds) almost immediately."